A footprint made by theropod dinosaur, found on the Isle of Syke.
Photograph: Paige dePolo/University of Edinb/PA

It’s now a windswept island boasting pine martens, red deer and puffins. But 170 million years ago, some very different beasts were leaving their mark on the Isle of Skye.

Researchers have unearthed a new site of about 50 tracks, some as big as a car tyre, from dinosaurs that roamed the island during the Middle Jurassic.

The study, published in the Scottish Journal of Geology, builds on previous dinosaur finds on the island – not least a huge array of tracks discovered in the north of Skye in 2015 by the same team.

That site showed hundreds of footprints, almost all from enormous, long-necked, plant-eating dinosaurs known as sauropods. But the newly discovered site at Rubha nam Brathairean, or Brothers’ Point, reveals that these hefty beasts were sharing their spot with another type of dinosaur: a meat-eater.

“Anytime we find new dinosaurs it is exciting, especially in Scotland because the record is so limited and also because these are Middle Jurassic dinosaurs and there are very few dinosaur fossils of that age anywhere in the world,” said Dr Stephen Brusatte, a palaeontologist and co-author of the study from the University of Edinburgh.

Around 170 million years ago, shortly after the supercontinent Pangaea began to break up, the land that is now Skye was part of a smaller subtropical island, far closer to the equator, and replete with beaches, rivers and lagoons.

“This was a subtropical kind of paradise world, probably kind of like Florida or Spain today,” Brusatte. “[These prints] were made in a shallow lagoon – dinosaurs walking in very shallow water.”

One of Brusatte’s students stumbled across the tracks in 2016 while on a field trip along Skye’s coast. “The tide went out and we noticed them,” said Brusatte. “We knew that you could find these things in Scotland and if you were walking on tidal platforms and you saw holes in the rock, they could, possibly, be footprints.”

Mapping the site with drones and other camera equipment revealed about 50 dinosaur prints at the site in total, including what appears to be two lines of tracks.

Brusatte said the conclusion that the depressions were produced by dinosaurs came down to a number of factors.

“There was a kind of a left-right, left-right patterning,” he said. “They were all kind of the same shape, they were all generally the same size – they were pretty circular but they had little bits sticking out at the front and those are marks of toes.”

Some of the footprints, said Brusatte, were as big as a car tyre. “There were also handprints associated with those tracks – so these were made by a dinosaur walking all fours, a big dinosaur, and the dinosaur that fits the bill is a sauropod – one of these long-necked, pot bellied, brontosaurus-type dinosaurs,” said Brusatte, adding that they would have been up to 15 metres in length and weighed more than 10 tonnes. “They were the biggest things living on land at the time,” he said.

Brothers’ Point on the Isle of Skye, where the dinosaur prints were found. Photograph: Jon Hoad/University of Edinburgh/PA

But the team also found impressions made by three-toed dinosaurs, probably theropods. “These are the tracks of the meat eaters,” said Brusatte. “[There were] only footprints, no handprints: this was a dinosaur just walking on its hind legs,” he added, saying the creature would have weighed about a tonne and was around five or six metres in length. “Kind of a primitive cousin of a T-Rex,” said Brusatte.

Brusatte said the prints back up evidence from the 2015 site that suggests dinosaurs spent time pottering around lagoons.

“We think of dinosaurs as thundering across the land, which of course they did, but in the Jurassic dinosaurs had become dominant, they had spread all over the world and they were living in all sorts of environments, even on the beaches, even in the lagoons,” he said.

“These dinosaurs look like they were just lingering, they were just kind of loitering. This seems to be a snapshot into a day in the life of some dinosaurs and I think that is just pretty cool.”